heat transfer of submersible pumps

[Randall_James]

If you poke a pencil into that powerhead and drop it into the water, I bet you find a closer correlation to the readings against the heater. As the motor is brushless, it should require no more power even when locked up with the "obstruction" You will lose the water movement

 

[stugray]

I thought we closed this discussion with "Heat transfer of pumps - Engineers wanted"


Here's a quote that helped put that discussion to bed:


'This thread just doesnt die.

I dont care what type of energy we are talking about, mechanical, resistive heating, particle accelerator. The amout of energy consumed by the system is rated in WATTS. If you put X amount of watts into a closed system, it must ALWAYS end up as heat. There is just no way around that ( unless we defy the law of entropy/enthalpy ).

Moving water makes heat as well as resistive elements ( there is just a lag time waiting for the water to stop moving, once the water stops, clearly - it must have been dissipated as heat ) Where else does the energy go?!?

There have been plenty of discussions about "well this system isnt closed....." - OF COURSE, but when one asks the question


"adding a 50 watt pump creates as much extra heat as adding a 50 watt heater"

The answer is :




YES it creates exactly the same amount of heat in a closed system

OR

It May NOT create the same amount of temperature rise in an open system.

REGARDLESS - they make the same amount of heat. That is the definition of power.

Stu'


It all comes down to open vs closed systems.

Stu - again

 

[goby1]

I know, I tried to find that thread but it seemed to have slipped.... It would have been a great reference. Search didn't find it.. maybe a google.

G1

 

[BeanAnimal]

Stu, no matter how many times it is spelled out, some people will not get it, because they do not understand.

It's the same as the guy who does not want to work "overtime" becuase his "check is smaller" because they take "more" taxes out.

No matter how many times you try to explain to these morons, that, at the end of the year they get that money back (unless of course they cross into the next tax bracket), the just don't get it. They will fist fight over the fact that if you work overtime, you lose money.

Bean

 

[ChemE]

<a href=showthread.php?s=&postid=7312043#post7312043 target=_blank>Originally posted</a> by stugray
...If you put X amount of watts into a closed system, it must ALWAYS end up as heat. There is just no way around that ( unless we defy the law of entropy/enthalpy )...

Sorry but this isn't always true; just in reefkeeping. In fusion reactions some energy is converted into mass. This holds with Einstein's Law of Conservation of Mass-Energy and Einstein can beat up Kelvin any day of the week and twice on Sunday. Most here should know by now that I can't resist dropping a little science.

Now in a reeftank, the quote is 100% true. I'm just being accurate and difficult which are frequently the same thing.

 

[BeanAnimal]

Hrmm, that mass is still part of Einsteins universe, and therefore part of his entire Entropy theory... even if it does get sucked into a black hole and become infinitely massive.

 

[ChemE]

What if the fusion forged mass sprays into a nearby wormhole? Then it goes off Einstein's radar. Good think Hawking has his back.

But it still isn't heat.

 

[BeanAnimal]

bah... Einstein did talk about wormholes, because they are a mere anomole of the black hole. As you mention Hawking has his back, but there are a few things that still don't mesh. Not to mention that MIT (I think) experiment where they moved matter fast than the speed of light.

I have shelf full of "those" books and when I feel really smart, I dig into them just to show myself how little I really do understand.

 

[ChemE]

<a href=showthread.php?s=&postid=7316923#post7316923 target=_blank>Originally posted</a> by BeanAnimal
...I have shelf full of "those" books and when I feel really smart, I dig into them just to show myself how little I really do understand.

I've only got a half dozen of "those" books but then again I seldom feel really smart. It is fun to stretch your mind though and not much cooks one's noodle like thinking about 11 dimensional space.

Now that this thread has been thoroughly jacked...I'm out.

 

[Randall_James]

<a href=showthread.php?s=&postid=7316923#post7316923 target=_blank>Originally posted</a> by BeanAnimal
bah... Einstein did talk about wormholes, because they are a mere anomole of the black hole. As you mention Hawking has his back, but there are a few things that still don't mesh. Not to mention that MIT (I think) experiment where they moved matter fast than the speed of light.

I have shelf full of "those" books and when I feel really smart, I dig into them just to show myself how little I really do understand.

anomole (sp) :lol: must have been a typing anomaly

Break out the warp drives Scotty.... we gotta show them that the space ship we built that goes warp 1 allows a person to walk in the direction of travel at light plus 3mph :lol: is he not traveling faster than the speed of light? drat so much for that idea

 

[BeanAnimal]

My spelling sucks, and I don't even bother to look back anymore unless it is a business document or similar piece of paperwork. In all honesty I have lost my ability to spell since I started using MS word 10 years ago.

Randall I keep getting stuck on that chapter... isn' that the one after the spinning disk and the clock

Maybe I should go back to reading the easier reading of the fruitcake (billions upon billions...)

In all honesty, It does not make me feel any better that 99.99% of population of the world gets stuck on "some" chapter in the book... I still feel like ChemE and it just get me thorougly jacked that I don't understand all of it.

I'm out too!

 

[Randall_James]

This argument has come and go here numerous times and frankly you can not teach the entire world science

just stop and think that that 99 percentile have no recall of the basic laws of physics and so thermodynamics and all the associated theory is just moot... Same thing goes for those who think it is "cold" in space, the brainy guys just think it is a lack of heat in the end does it even matter ? not really, you still turn into a popcicle if you go there

 

[BeanAnimal]

Theres no such thing as space, NASA is just lying to us becuase they don't want us to go there and find all the free weenie tots.

 

[Randall_James]

<a href=showthread.php?s=&postid=7318015#post7318015 target=_blank>Originally posted</a> by BeanAnimal
Theres no such thing as space, NASA is just lying to us becuase they don't want us to go there and find all the free weenie tots.

ut oh, going to have to tell about the moonscape on the back lot where the lunar landing was filmed too then

 

[BeanAnimal]

Wow this has drifted way off topic.

For thos skeptics (I was one myslef and still sometimes teeter on the edge) http://www.clavius.org/index.html is one of the best put together sites I have ever seen. It pretty much shows that the "conspiracy" stuff is fun, but not very coherent if you really put it all together.

 

[goby1]

That site taught me that the moon skeptics have a better stance than the anti-evolutionists.

I wouldn't have put it past the gov't, but there were so many people involved with that project for it not to have been real. There is an ether though

G1

 

[BeanAnimal]

Was that your first look at the clavius site?

Yeah... way to many people involved for somebody not to have spilled the beans (no pun) by now.

 

[stugray]

Yeah... the 'Moon hoax' was propagated by people who dont understand the physics, but they refute scientific evidence 'because it's common sense'. If space travel ( and the understanding thereof ) was easy, we'd all be vacationing on the moon.

It reminds me of an argument that stated "The builders of the great pyramid MUST have been assitied by aliens because they knew the value fo PI to 30 decimal places".

This was due to the 'observation' that if you drew a circle around the great pyramid, the circumference of the circle was EXACTLY PI TIMES the distance from corner to corner.

BRILLIANT!!

Stu

 

[BeanAnimal]

pi are sqaure only if your an alien

 

[ChemE]

Pi are round, cornbread are square!